A FEM Analysis Of Welding Deformation Which Happened The Bus Skin

The thin low carbon steel sheet is used as the material of the outer skin of the coach.The welding deformation is easily occur because of the welding between skin and skeleton and thus influence the quality of the next procedure(painting) and the appearance of the complete vehicle.The outer skin of the vehicle is the research object of this article, the digital simulation of the welding deformation is done by the method of the FEA.It provides for the constitution of the reasonable body welding technics in the real product process.This article in studies and summarizes in the foundation which the predecessor works, according to the enterprise actual situation, has established the finite element model, Carries on the coach outer skin welding temperature field, the stress bias field value simulation using the ANSYS software.This article uses the indirect method, carries on the temperature field first the analysis, then the temperature field analysis result took the stress strain field analysis the load, carries on the analysis.In welding process, along with heat source migration, entire weldment temperature along with time and spatial variation; The physical characteristic of the material also changes when the temperature changes.There are also Latent Heat and Phase Change.So the simulation of the welding process is a typical nonlinear issue. Because this article uses the welding method which is continuously welds, heats up the electric arc is continuously the even migration, Used ANSYS parametrization design language (APDL) regarding motion realization this article to compile the subroutine, and Uses the finite element separate the thought, uses the APDL language fully the branch and the circulation function, Has defined the array parameter and the heat flow density expression. And changes regarding the melting when latent heat processing, this article has profited from predecessor's experience, neglected the solid state to change the latent heat. Regarding melting latent heat, when definition compared to heat capacity through processes in the melting point temperature place for a very big step value. When computation, this article has selected the Gaussian distribution heat source model, passed through several relapses to determine the appropriate grid division and the time length of stride. Exerts the load the heat source by the heat flow density form, simultaneously had considered the convection heat transfer, when carried on the thermal analysis has used surface effect unit SURF151, has obtained the ideal stable temperature field. The temperature field value simulation is the entire computation foundation, also is most essential one step. When carries on the stress, the bias field analysis, the application temperature field computation model and the grid division, transforms first the hot unit as the corresponding...